This invention relates to a cooling system for cooling an electronic system, such as a computer, or the like, with a liquid coolant.
Since a conventional cooling system uses liquid as a coolant, it is conceivable that a system, which comprises a heat exchange unit, may be used for cooling the coolant which has been heated by an electronic system which is to be cooled. A pump feeds the coolant from the heat exchange unit via an expansion tank to the electronic system. A sensor detects the temperature of the coolant which is fed from the pump. A control circuit controls the operation of the heat exchange unit in response to the temperature detected by the sensor.
In such a cooling system, the operation of a compressor provided in the heat exchange unit is started when the temperature detected by the sensor exceeds a first threshold value. Its operation is suspended when the detected temperature falls below a second threshold value which is set lower than the first threshold value. However, since the start and suspension operations of the heat exchange unit are repeated quite frequently, the durable life of the compressor in the unit is unavoidably shortened. On the other hand, if the difference between the first and the second threshold values is set at a large value to reduce the frequency of the above-mentioned operations, the minute and delicate adjustment of the temperature of the coolant cannot be achieved.
An object of this invention is, therefore, to provide a cooling system which is free from the above-mentioned disadvantages.